My situation is this in. I define a ProxyPass, to different the incoming request ( for example, www.example.com ) to the relevant port ( for example, port 81), then at the httpd.conf for the example.com, I will have a few rewrite rules, some of them will direct the request to other domains. The reroutes will at most occurs 3 times. This means that the www.example.com will be reroute to port: 81, and if it matches a certain condition, then it might be rewroute to blog.example.com. And the blog.example.com will then be reroute to port 83 of another pc.

If you're using ProxyPass it's not routing it's proxying. So in the worst case scenario you have the overhead of setting up two additional TCP/IP connections and moving content over these connections, i.e.